Wijn zonder (toegevoegde) sulfiet

Memories from a wine producer: Puro, the first Chianti without added sulfites.

For many years I have been questioning myself and did research to understand the real need or no need of sulfites, spoke to customers who were constantly telling me that they can drink only organic wines (where sulfites are usually limited) because they are allergic to sulfites, so I came to a conclusion:
“We left the city to live a better and healthier life in the country, which consequently leaded us to farm organically to respect and protect the environment. We don’t use chemicals, no pesticides, herbicides, fungicides, insecticides or chemical fertilizers, we diversify the cultures and alternate the different varietal, we use green energy, recycle, produce (organically of course) our own
vegetables from antique seeds, high quality extra virgin olive oil and wines with low sulfites to ensure a healthier diet and, in a certain way, we are responsible of the health of our consumers. So why not try to produce our wines WITHOUT SULFITES? “
NB. Totally without sulfites is impossible since sulfites are naturally occurring compounds that plants produce to protect themselves from microbial infection. Sulfites develop naturally as a byproduct of fermentation. Naturally occurring sulfites are generated in very small amounts ranging from 5 to 10 mg/liter and the presence of natural sulfites is so small that it normally does not present a problem to anyone.

First of all what are sulfites?
The term “Sulfites” is commonly referred to sulfur dioxide (a gas whose chemical formula is SO2) and its salts derived. These are substances widely used in the food industry as preservatives, antioxidants, and, in certain cases, such as dyes to reduce the browning of various foods. You do not find them only in the wine, but also in many other foods. The harmful effects of sulfur dioxide and sulfites on health have been and are still the subject of numerous studies, because of their widespread use in the food and the growing attention of consumers to the relationship between food and health. Sulfites are potential “allergens” and can cause respiratory problems in people with asthma, but can also lead to gastric irritation, adversely affect the absorption of vitamin B1 and, in women, increase the risk of osteoporosis. Finally, the ability of sulfite to reduce the flow of oxygen to the brain during digestion generates the well-known symptoms of head aches.
The results of scientific research have prompted the World Health Organization (OMS) to define for sulfites an Acceptable Daily Intake (ADI) of 0.7 mg per kg of body weight. This means that a person weighing 70 kg should not take more than 50 mg of sulfites a day! Consuming 330 ml of wine containing 150 mg / litre of sulfites, would be enough to exceed the maximum limit, without even considering sulphites present in other foods! But wine is one of the few products that carries the words “contains sulfites” on its label.
The level of sulfites in wine is measured in mg/liter, or parts per million. In the United States, conventionally made wines are permitted to contain up to 350mg/liter of sulfites, where as in Europe the limit is of 200. European regulation on organic wine limits the threshold level of sulfites to 100 mg/liter, and levels are generally much lower (around 40 to 80).
By the current USDA Organic Standard, any wine, foreign or domestic, can contain only naturally occurring sulfites (and the level should be less than 10mg/liter*) to be marketed and sold as an “Organic Wine”. This means that the European Organic Wines that have added sulfites or that have more than 10mg/liter, in the US should be referred to as “wines made from organic grapes”

*On January 1st, 1987 the United States mandated that all wines with over 10ppm sulfites, added or naturally occurring bear the words “Contains Sulfites” on the label. The law was meant to warn the population that was allergic to sulfites. In Europe this inscription has been imposed recently and this warning must be in the language of the country where the wine is exported.
Wines with less than 10 mg/liter are not required to carry the warning: that does not mean, however, that they are 100% sulfite free. Since all wines naturally contain very small amounts of sulfite, the exact labeling for these wines should be “no added sulfites”.
In wine, sulfites are used for their antiseptic function against microorganisms (first of all on bacteria but also possibly on the yeasts) and for their antioxidant action to counteract the degradation over time of some characteristics of the wine. Winemakers have been adding sulfur to wine for hundreds (and possibly thousands) of years to help prevent it from spoiling.
Just about every conventional winemaker adds sulfites to his wine to keep it fresh and stable in the bottle. Many go as far as to maintain that good quality wine cannot be made without them as there are multiple advantages for the use SO2 in winemaking: From the moment the grapes are harvested until the moment the bottle of wine is opened and it is finally consumed, SO2 has very important properties.
It is antiseptic and antimicrobial (molecular SO2) as it inhibits the growth of all types of microorganisms, such as yeasts and bacteria. In practice what it does is to chemically help the winemaker to inhibit bacterial spoilage (more importantly on lactic acid bacteria, but also, to a lesser extent, on acetic acid bacteria), Brettanomyces, Zygosaccharomyces, and mycodermic yeasts (flor yeasts) growth, prevention of yeast haze formation, unwanted malolactic fermentation, and secondary fermentation of wines that contain residual sugar (dessert white wines mostly).
Before fermentation, SO2 (and its antioxidasic properties) protects must from oxidation; it favors the dissolution of organic acids, minerals and the so important (in red winemaking) amalgamation of tannins and anthocyanins to the wine; SO2 also binds with ethanal and other similar chemical compounds (such as ketonic acids) helping to avoid a possible perception of a wine being “flat”.
As an antioxidant, it works because it binds with dissolved oxygen and it is much more important during wine storage than during winemaking. What it means is that it can protect the wine from chemical oxidation, but it doesn’t avoid enzymatic oxidation. It is also a helping tool to the establishment of a low oxidation-reduction potential and wine aroma and taste development during the aging process is heavily dependent on it. It also reduces the rate phenolic polymerization that causes color loss observed during the aging process. Not to mention that when a wine is aged in a barrel, it may not be sufficient to add SO2 to the wine, but rather a disinfection of the barrel with SO2 gas (or burning sulfur) is necessary to prevent the growth of Brettanomyces.
So what are the drawbacks or issues with the use of SO2 in winemaking? Of course, first and foremost, excessive doses must be avoided, not only because of health reasons, but also because it can have a negative impact on aromas and flavors (pungent and sulforous).
However, the issue with SO2 is not about only excessive additions of it, even low doses of SO2 added during a pre-fermentation skin contact promote the extraction of protein. This is not good, especially in white winemaking, as a larger quantity of bentonite will be needed to stabilize the wine. This may cause a negative impact in the organoleptic properties of the wine (mainly aroma loss).
As you can notice, the use of SO2 in winemaking is a complex subject but with the years we noticed that some factors are involved in its efficacy. The most important ones are: pH, residual sugar and alcohol content. What it means is that these factors will determine the amount of SO2 that needs to be added to determine a final safe level of free SO2 in the wine. High acidity and alcohol make the environment more hostile to bacteria, while the presence of sugar has the opposite effect.
Temperature is also a very important factor: the lower the temperature, the better the efficacy of SO2 and the slower the oxidation of the wine. In fact: the higher the acidity the less SO2 needs to be added; the higher the alcohol content, the less SO2; and the lower the residual sugar, the less SO2 needed.
A better understanding of the chemistry of SO2, combined with an increased hygiene in the cellar and very healthy grapes, has enabled us to substantially reduce the SO2 concentrations used during the vinification process, without reducing the quality and age-ability of the wines. This being said, Chianti Rufina wines are well known for their higher acidity, alcohol content is not an issue since organic farming reduces crop and consequently concentrates sugars which develop higher alcohol (in a certain way alcohol also preserves wine), we have available the best raw materials: vital, flavorsome organic grapes and there is absolutely no residual sugar in our Chianti. We have all the credentials, so why not try!We produced Puro for the first time in 2011.
Producing an age worthy, stable Chianti without adding sulfites is a scientific, technical, and artistic challenge and I finally convinced my father, my husband Dimitri, Duccio the cellar master and our wine makers, Stefano and Federico to start this adventure with me.
The 2011 “Puro” started with extremely healthy, ripe Sangiovese grapes. The organic grapes came only from selected vineyards at high altitude (450 meters above sea level). They were manually harvested and displayed excellent fruitiness and acidity, typical of Rufina. It was vinified to complete dryness with no residual sugar in stainless steel tanks. After fermentation the wine was let to set in a vacuumed tank for a couple of months and in march 2012 it was sterile filtered and vacuum bottled. There was no contact with oxygen. Special “diam” corks were used.
These corks allow almost no oxygen to penetrate and make contact with the wine. During maturation the bottles were kept at low temperatures.
The entire approach has been cautious. At each stage of its development, “Puro” has been tasted, tested, and analyzed.
It contained only 12mg/liter of natural sulfites, produced from the yeasts of the grape skins during fermentation. Therefore, the label had to state “Contains sulfites,” but went on stating “No sulfites added.”
Puro 2011 started off dry and tannic, but after 15 minutes or so, the strawberry, licorice fruitiness of the Sangiovese started to show itself a bit. An hour later the wine opened up wonderfully. It was sound and delicious, a good reflection of the terroir of Rufina and of the Sangiovese vine.
The goal for the following vintages was to improve the style and produce it with fewer than 10mg/liter in order to remove “Contains sulfites” from the label. We are now able to control the natural occurring sulfite levels and are experimenting a version aged in wood which has become Puro Riserva.
In the latest vintages I like its pure aromas, its fruitiness, its full expression of the grape and terroir and I think Puro is the proof that you can have bright, pure wines without adding sulfites. Of course we will only make the wine this way in ideal conditions.
Faye Lottero
Fattoria Lavacchio